1. Field of the Invention
The present invention relates to wireless communication systems. More particularly, the present invention relates to an improved integrated wireless-wireless system (IWWS) which eliminates the requirement of dual-tone modulation frequency (DTMF) signaling between the wireless and wireline sections.
2. Description of the Related Art
Increasing demand for convenient and universally available wireless communication is driving the development of new networking techniques that accommodate mobile voice and data users who move throughout cites, broad geographic regions, and even between countries.
As used throughout this description, "wireless" refers to a broad class of communication systems and technologies utilizing open air interface. Mobile telephone, cellular telephone, wireless local-loop, paging, and personal communication systems (PCS) are ready examples of wireless communication systems adaptable to an IWWS architecture. As used throughout this description, "wireline" refers to network elements normally associated with the public switched telephone network (PSTN), but may also include ISDN, public databases and similar landline based services.
The term "communicating!" is used to reference a broad class of information exchange between network sections and elements. Communication may be made via hardware links and/or open-air interfaces, and may involve complex, bi-directional hand-shaking as is commonly understood in the telecommunications field. The term "call" is used to reference any party to party data transfer such as PCS, as well as traditional voice telephone calls.
Historically, the demand for wireless communication has consistently exceeded the capacity of available technology. Recent efforts to expand wireless communication and to better import wireline features and performance into wireless communication has resulted in dramatic changes to network architecture. An IWWS has been proposed in U.S. application Ser. No. 08/942,895, filed Oct. 2, 1997 which is incorporated herein by reference.
The IWWS provides an architecture which does not necessarily require a Mobile Switching Center (MSC), but which effectively uses existing wireline switching equipment and capabilities to provide integrated wireless/wireline services to users. The resulting "meld" of wireless communication system components with wireline network components offers many commercial and technical advantages to service providers. For example, the IWWS architecture allows service providers to reduce network equipment purchases, to lower maintenance costs, and to simplify equipment integration. In fact, service providers offering wireline and wireless services have the option of leveraging existing wireline capabilities, without recourse to a separately procured MSC, to effect lower cost wireless services.
Not only are hardware costs lowered by the elimination of the MSC, but also service providers may easily integrate wireline and wireless billing requirements, readily import the rich features currently offered in wireline service into wireless service, integrate wireline directory numbers, and centralize physical operations and maintenance centers.
However, the proposed IWWS is not without drawbacks. As presently proposed, the GR-303 signaling interface which connects the wireline and wireless sections in the IWWS requires that dual-tone modulation frequency (DTMF) signaling be implemented in the wireless section. That is, since GR-303 hybrid signaling is an analog technique, i.e., a technique using Robbed Bits Signaling (RBS), and not a message based technique, the called party's number must be sent from the wireless section to the wireline section using DTMF signaling. Such a requirement necessitates undesired hardware and firmware in the wireless section to handle DTMF signaling.
Further, call setup is delayed by the amount of time required to apply and detect the dial tone at the wireline switch, and the subsequent time required to transmit, digit by digit, the called party's number from the wireless infrastructure to the switch via the GR-303 interface.